Java 奇怪的断言包含了行为_Java_List_Junit

Java 奇怪的断言包含了行为

java list junit

Java 奇怪的断言包含了行为,java,list,junit,Java,List,Junit,我有一个非常简单的Pair类，定义如下： public class Pair<L, R> { private L left; private R right; public Pair(L left, R right) { this.left = left; this.right = right; } public L getLeft() { return this.left; }

我有一个非常简单的Pair类，定义如下：

public class Pair<L, R> {

    private L left;
    private R right;

    public Pair(L left, R right) {
        this.left = left;
        this.right = right;
    }

    public L getLeft() {
        return this.left;
    }

    public R getRight() {
        return this.right;
    }

    public String toString() {
        return String.format("(%s, %s)", left, right);
    }

    public int hashCode() {
        int hashFirst = left != null ? left.hashCode() : 0;
        int hashSecond = left != null ? right.hashCode() : 0;

        return (hashFirst + hashSecond) * hashSecond + hashFirst;
    }

    public Boolean equals(Pair other) {
        if (other == null) {
            return false;
        }

        return left.equals(other.getLeft()) && right.equals(other.getRight());
    }
}

public class Position {

    private Pair<Integer, Integer> pair;

    public Position(Integer x, Integer y) {
        this.pair = new Pair<Integer, Integer>(x, y);
    }

    public Integer getX() {
        return this.pair.getLeft();
    }

    public Integer getY() {
        return this.pair.getRight();
    }

    public boolean equals(Position other) {
        if (other == null) {
            return false;
        }

        boolean b = getX() == other.getX() && getY() == other.getY();
        System.out.println(String.format("%s.equals(%s): %s", this, other, b));
        return b;
    }

    public int hashCode() {
        return pair.hashCode();
    }

    public String toString() {
        return String.format("(%d, %d)", this.pair.getLeft(),
                              this.pair.getRight());
    }

}

    [junit] ------------- Standard Output ---------------
    [junit] JUnit version is: 3.8.2
    [junit] contains: false
    [junit] (7, 6).equals((7, 6)): true
    [junit] (7, 6).equals((7, 6)): true
    [junit] (7, 6).equals((12, 7)): false
    [junit] (7, 6).equals((12, 7)): false
    [junit] (7, 6).equals((12, 7)): false
    [junit] (7, 3).equals((7, 4)): false
    [junit] ------------- ---------------- ---------------
    [junit] 
    [junit] Testcase: testListContainsSuccessDiff took 0.005 sec
    [junit]     FAILED
    [junit] null
    [junit] junit.framework.AssertionFailedError
    [junit]     at com.group7.dragonwars.tests.PositionTests.testListContainsSuccessDiff(PositionTests.java:92)
    [junit] 
    [junit] Testcase: testListContainsFail took 0 sec
    [junit] Testcase: testYEquality took 0 sec
    [junit] Testcase: testSymmTrue took 0.014 sec
    [junit] Testcase: testSymmFalse took 0.001 sec
    [junit] Testcase: testHashSetSame took 0 sec
    [junit] Testcase: testListContainsSuccess took 0 sec
    [junit] Testcase: testCreationY took 0 sec
    [junit] Testcase: testEquality took 0.001 sec
    [junit]     FAILED
    [junit] expected:<(7, 6)> but was:<(7, 6)>
    [junit] junit.framework.AssertionFailedError: expected:<(7, 6)> but was:<(7, 6)>
    [junit]     at com.group7.dragonwars.tests.PositionTests.testEquality(PositionTests.java:43)
    [junit] 
    [junit] Testcase: testInequality took 0.001 sec
    [junit] Testcase: testXEquality took 0 sec
    [junit] Testcase: testCreationX took 0 sec
    [junit] Test com.group7.dragonwars.tests.AllTests FAILED

然而，

.contains（）

失败了。什么是…？

如果在equals（）方法中添加

@Override

注释，您将看到问题。参数类型必须是

对象

，而不是

位置

@Override
public boolean equals(Object other) {

另外，

Pair.hashCode（）

中有一个输入错误

您希望位置和对上的相等值接受一个对象——您只是用接受对的声明重载它

另外，您在Pair上的hashCode实现也很奇怪：）可能使用Apache EqualBuilder和HashBuilder类